Yes. When you click Create Audiences, creation is sent to run in the background on the server, and you're told you can close the page. When the process finishes, a notification arrives in the system bell (and a push notification in the iOS app, if you use it) telling you how many audiences were created and whether there were errors. If you return to the Create Audiences page while the process is still running, the progress panel is restored automatically and keeps updating in real time, item by item.